Synthesis of (7<i>S</i>,15<i>S</i>)- and (7<i>R</i>,15<i>S</i>)-Dolatrienoic Acid<sup>1a</sup>
作者:Jonathan J. Duffield、George R. Pettit
DOI:10.1021/np000502q
日期:2001.4.1
stereospecific synthesis of (7S,15S)- and (7R,15S)-dolatrienoic acids (2) was achieved using an approach consisting of 16 linear steps. The C-11--C-16 unit was prepared in seven steps from ethyl (S)-lactate and coupled using a trans-selective Wittig--Schlosser reaction to the C-7--C-10 fragment. Chirality at the C-7 position was introduced using an Evan's-type chiral auxiliary in a cobalt-mediated Reformatsky
(7S,15S)-和(7R,15S)-十二碳三烯酸(2)的立体有择合成是使用由16个线性步骤组成的方法实现的。C-11--C-16单元是从(S)-乳酸乙酯中分七个步骤制备的,并使用反式Wittig-Schlosser反应与C-7-C-10片段偶联。在钴介导的Reformatsky反应中,使用Evan's型手性助剂在C-7位置引入手性,得到(3S,11S)-醛24。随后与Wittig反应,由三步反应得到的酸形成acid盐, (7S,15S)-十二碳三烯酸,强癌细胞生长抑制性环二肽dolastatin 14(1)的四种非对映异构体之一。第二种非对映异构体(7R,15S)-十二碳三烯酸